Fastener assemblies



Oct. 25, 1960 c. c. BREWER ET AL 2,958,070

FASTENER ASSEMBLIES,

Filed July 15, 1957 Uni Stat s P te FASTENER ASSEMBLIES Filed July 15, 1957, Ser. No. 671,809

4 Claims. (Cl. 339-270) This invention relates generally to fastening devices; more particularly, it relates to fastener assemblies primarily for use in attaching apertured connectors to terminals or other mountings.

Heretofore, the use of apertured connectors, such as enclosed spade lugs, has been difficult and often impractical because of the lack of a terminal assembly capable of providing a firm connection under adverse environmental conditions and adapted for convenient attachment and detachment of connectors. Using conventional means for mounting an enclosed spade lug upon a post or other terminal member, it has been necessary to re move a retaining member, such as a nut, to attach the lug, and to replace this retaining member upon the post after the lug has been engaged upon the post. As is well known, this process is time consuming and tedious. It is also well known that retaining members, during the process of removal and replacement, are often dropped into electrical assemblies, requiring considerable time and effort for retrieval. Sometimes, it is substantially impossible to retrieve a dropped member from complex assemblies, and damage and electrical shorts can result. Despite these and other disadvantages, enclosed spade lugs are used because they are necessary for many applications where secure permanent connections are needed to withstand adverse environmental conditions.

In order to avoid the dificulties presented in installing and removing enclosed spade lugs, a type of spade lug having *a bifurcated metal end has been utilized. Such an end may conveniently be positioned under a retaining member on a post or bolt without requiring removal of the retaining member from the post or bolt. It is only necessary to loosen or raise the retaining member upon its post, insert the bifurcated spade lug, and tighten the retaining member against the lug. Such a bifurcated structure is not acceptable in many applications, because of its tendency to work loose from a post under adverse environmental conditions, such as vibration or shock.

It is, therefore, an object of the present invention to Overcome the foregoing disadvantages of prior art devices by providing a new and improved fastener assembly primarily for use with apertured connectors.

It is an object of this invention to provide a fastener assembly wherein the parts of the assembly need not be separated in securing or unsecuring apertured connectors. It is another object of the present invention to provide a fastening assembly wherein resilient elements of the assembly are deformed during the attachment of a connector to provide means for securing the connector and are returned to their original configuration during detachment of the connector.

Other objects and features of the present invention, as well as many advantages thereof, will be apparent to those skilled in the art from a consideration of the remainder of this description, the appended claims and the accompanying drawings, in which:

Figure l is a perspective view showing a terminal assembly of the present invention mounted on a terminal board? Figure 2 is a perspective view showing the terminal assembly of Figure 1 in operative position for securing apertured connectors;

Figures 3a, 3b, 3c and 3d are elevational views, partially in section, of the fastener assembly of Figures 1 and 2, illustrating the operations employed in utilizing a fastener assembly of the present invention in securing and unsecuring an apertured connector;

Figure 4 is an elevational view, partially in section, showing the terminal assembly of Figure 1 with the parts in disengaged relation;

Figure 5 is an elevational view, partially in section, showing the terminal assembly of Figure 1 with the parts in engaged relation for securing connectors;

Figure 6 is a cross-sectional View taken at line 6-6 of Figure 4; and

Figure 7 is a cross-sectional view, similar to that of Figure 6, showing certain features of a modified form of securing member utilized with the present invention.

Referring to the drawing, there is shown a preferred embodiment of the terminal assembly 10 of the present invention, which includes a post 12 and a generally cylindrical securing member 14. As shown in Figures 3, 4, and 5, post 12 preferably includes a shaft portion 20 adapted to extend through an opening 18 in a terminal board 16 to accommodate a nut 22 which threadedly engages a threaded portion 24 to secure post 12 to board 16. Terminal board 16 will be understood to be merely exemplary of a variety of base members that may be utilized with the present invention. It may be formed of conductive material or it may be made of a nonconductive material, such as a laminated type of printed circuit base structure. Adjacent to shaft portion 20 is an enlarged cylindrical section 26 of post 12 which bears against terminal board 16. A fmstro-conical or tapered section 28 extends from section 26 and "has a reduced end 30 remote from terminal board 16. Section 28 is frustro-conical in configuration for reasons which will be understood from discussion further in this description. Preferably this section has the shape of a frustrum of a right circular cone, but this configuration is not the only one which is operable with the present invention. Extending from reduced end 30 of section 28 is a threaded bolt portion 32 of post 12, bolt portion 32 being co-axial with section 28 and cylindrical section 26.

Bolt portion 3 2 of post 12 is adapted for threaded engagement with a threaded bore 34 in the upper or head portion 36 of securing member 14. An end 38 of securing member 14 is provided with means for receiving an installation tool (not shown) with which securing member 14 may be rotated upon bolt portion 32. This may be a slot 40, as shown in Figures 4 and 5, for accommodating a screwdriver, it may take the form of a hexagonally shaped end (as shown in Figures 1 and 2), for accommodating a wrench, or it may take other forms.

A pluralityof fingers 44 constitute the lower portion of securing member 14, and are preferably formed in tegrally with member 14 by cutting a plurality of slots 46 such that fingers 44 and slots 46 extend from the end of threaded bore 34 to the lower end of member 14. As shown in Figures 3 and 5, fingers 44 are thinner in cross-section than the Wall of head portion 36'which defines bore 34 This enhances the resilient or spring like characteristic of the fingers, the importance of which will be understood from later discussion herein. Securing member 14 is preferably constructed of a metal which provides a good spring-like or resilient characteristic for fingers 44 and which will enable these fingers to resume their normal configurations after long periods of distortion. Beryllium copper has been foundin practice to be a satisfactory material for this purpose. Obviously, other materials may be utilized. Obviously, the number of slots 46 and fingers 44 may vary among different embodiments of the present invention. The resistance of each finger to bending will obviously vary inversely with the number of fingers. It has been found in practice that effective results have been obtained through the use of six fingers 44, as shown in Figures 2 and 6. Effective performance has been obtained from a securing member with four fingers (such as is indicated in Figure 7).

The particular embodiment illustrated in the drawing is adapted for use primarily with a common spade lug 50 (best shown in Figure 1) having a central opening 52 formed in a metal end 54 thereof. Spade lug 50 is designed for attachment to at least one wire 56, as shown.

In the utilization of the terminal assembly of the present invention, post 12 is mounted to a base, such as a terminal board, by inserting shaft portion 20 through an opening in the base and securing it to the base by such means as the rivet shown in Figures 4 and or by means of the threaded engagement of a nut 22 with a threaded end 24 of shaft portion 20, as shown in Figure 3. Securing member 14 is then engaged with threaded bolt portion 34, as shown in Figure 4, with the threads of bore 34 slightly engaging bolt portion 32. Spade lug 50 is passed downward over securing member 14, as illustrated in Figure 3b, until it is adjacent to terminal board 20 with its end 54 disposed about cylindrical section 26. Securing member 14 is then rotated, as by a screwdriver engaging slot 40, to thread it downward on post 12. During this downward movement produced by rotation, a bevel 42 at the lower ends of fingers 44 engages frustroconical section 28. Further downward movement of member 14 obviously causes fingers 44 to be forced outward by frustro-conical section 28, as illustrated in Figures 30 and 5.

This outward distortion of fingers 44 enlarges the circumference of the lower end of securing member 14 to a size larger than opening 52 of spade lug 50, to permit member 14 to secure end 54 of lug 50, as is best shown in Figure 5, after securing member 14 is further rotated until fingers 44 contact lug 5t Reasonable care should be exercised to prevent deformation of fingers 44 by the exertion of excessive turning force on securing member 14. Bevel 42 is preferably formed at such an angle that the full edge presented by the thickness of each finger is in contact with end 54 of the spade lug, so that a locking action is provided by these relatively sharp edges, which tends to prevent loosening and counter-rotation of securing member 14. This locking action is somewhat similar to the well-known action produced by a common lock washer, the edges of fingers 44 gouging into end 54 of the spade lug.

It is apparent that more than one spade lug 50 may be secured by a single securing member 14, this being illustrated in Figures 2 and 5 of the drawing. The axial length of cylindrical section 26 may be selected for any particular embodiment of the present invention to accommodate the desired number of spade lugs.

In removing spade lug 50, securing member 14 is raised from the lug by rotating, as indicated in Figure 3d. With the raising of member 14, resilient fingers 44 automatically return to their unextended positions relative to securing member 14, as they ride upward upon frustro-conical section 28. Spade lug 50 may then be lifted past securing member 14 and from terminal assembly 10.

Those versed in the art will realize that a number of modifications may be made in the constructions shown without departing from the essential features of the present invention and will understand that the basic principles of this invention are applicable to a wide variety of different structures. As an example of such a modification fingers 44 can be formed as separate members of wire or spring steel, and attached by welding or soldering to head portion 36 of securing member 14. As another example, cylindrical section 26 of post 12 could be eliminated, although its use is preferable because it not only provides accommodation for a thick spade lug or a number of spade lugs, but it also assures that fingers 44 are spread sufficiently far to engage an end 54 of a spade lug.

Although specific embodiments of the present invention have been illustrated and described in detail, it is to be clearly understood that the same are by way of illustration and example only; it is to be understood that the invention is not limited thereto, as many variations will be readily apparent to those versed in the art and the invention is to be given its broadest possible interpretation within the terms of the appended claims.

We claim:

1. A fastener for securing an apertured connector to a base, comprising a post member attached to said base so as to extend therefrom and having a tapered portion intermediate of a threaded portion and said base, a securing member having a threaded bore and having a plurality of fingers extending parallel to the longitudinal axis of the post member, said fingers being of resilient material whereby they are spread upon overriding said tapered portion as said securing member is threaded on the post member toward said base and are unspread as the securing member is threaded away from the base, and at least one apertured connector adapted to be secured between said base and said fingers upon said spreading of the fingers and adapted to be moved past the fingers upon the unspreading thereof.

2. A fastener for attaching an apertured connector to a terminal base, comprising a post member having a threaded shaft portion extending from said base member and having a tapered portion between said shaft portion and said base member, means for attaching said post member to said base member, and a securing member having a threaded bore adapted to engage said threaded shaft portions, said securing member being slotted to form a plurality of fingers extending parallel to the longitudinal axis of the post member, said fingers being of resilient material whereby they are spread upon overriding said tapered portion as said securing member is threaded on said post member toward said base and are unspread as the securing member is threaded away from the base, an apertured connector interposed between said base and the end portions of the fingers and adapted to pass over said fingers upon the unspreading of the fingers, and means on said securing member for receiving an installation tool.

3. A fastener for securing an apertured connector to a base, comprising a post member extending from the base and having a tapered portion, a securing member adapted to engage the post member, cooperating means on said members for attaching the securing member on the post member and allowing the securing member to be moved towards and away from the base, said securing member having a plurality of fingers extending parallel to the longitudinal axis of the post member, said fingers being of resilient material whereby they are spread upon overriding said tapered portion as the securing member is moved on the post member toward said base and are unspread as the securing member is moved away from the base, and an apertured connector adapted to be secured between said base and said fingers upon said spreading of the fingers and adapted to be moved past the fingers upon the unspreading thereof.

4. A fastener for securing an apertured connector to a base, comprising a post member attached to said base so as to extend therefrom and having a tapered portion intermediate of a threaded portion and said base, a securing member of unitary resilient metal construction having a threaded bore and having a plurality of fingers extending parallel to the longitudinal axis of the post member, said fingers being of resilient material whereby they are 5 6 spread upon overriding said tapered portion as said se- References Cited in the file of this patent curing member is threaded on the post member toward UNITED STATES PATENTS said base and are unspread as the securing member 1s threaded away from the base, and at least one aper- 1,092,037 a 1914 tured connector adapted to be secured between said base 5 1325297 Wfllard May 1917 and Said fingers upon said spreading of the fingers and 2644929 KQmPf July 1953 adapted to be moved past the fingers upon the unspread- 2,697,375 Bnsack 1954 ing thereof, said finger end portions having edges adapted 2760399 Rea 1956 to gouge into the apertured connector and provide a locking action to resist unthreading of the securing mem- 10 her away from the base. 

